Type I (Werdnig-Hoffman Disease): Early onset and diagnosis (before 3 months), with
severe intrauterine growth retardation, polyhydramnios, and tongue
fasciculations. Child never sits or walks. There is difficulty with
swallowing and feeding. Respiratory function is always severely impaired:
diaphragmatic breathing, respiratory infection, and distress. Absent deep
tendon reflexes, hypotonia, and weakness, but normal intelligence and no
sensory loss are observed. Restricted joint mobility and kyphoscoliosis are
also frequent. Death before age of 2 years old is common but does not always
occur.